In a small bowl, combine the cumin, coriander, turmeric, smoked paprika, and only 1 teaspoon of garam masala. Set aside.
Heat oil in a large skillet over medium heat. Add onion and serrano pepper. Sauté until softened and onions are lightly golden. About 4-6 minutes.
Lower heat one notch and add the garlic and ginger. Sauté for 30-60 seconds until fragrant.
Add the spice mixture and sauté for 30 seconds until fragrant.
Add tomato purée, sugar, and 1/2 teaspoon of salt. Bring to a simmer, then lower the heat to maintain a mild to moderate simmer. Cook for about 10 minutes until it thickens up. Stir often to prevent sticking or burning.
Now add the broth, chickpeas and remaining salt. Cover with a lid but slightly offset it on the pan to release steam. Raise the heat to get things moving, then lower the heat to maintain a mild simmer. Stir occasionally. Cook for 10-15 minutes until the liquid reduces and has a stew-like consistency (or desired consistency). (If you want it thicker, you can mash some chickpeas with a potato masher and stir).
Remove from heat and stir in lemon juice, cilantro, and remaining garam masala. Taste for seasoning and add more if needed. Top over rice and serve with naan, lemon wedges, and cut cilantro if desired. Enjoy!